1. Field of the Invention
The present invention relates to an apparatus and method for measuring concentration of a liquid-state refrigerant of a nonazeotrope refrigerant mixture and a heat pump including the apparatus, and more particularly, to an apparatus and method for measuring concentration of a liquid-state refrigerant of a nonazeotrope refrigerant mixture, whereby the concentration of the liquid-state refrigerant may be measured using a saturation pressure and temperature of the liquid-state refrigerant and an absorption type heat pump including the apparatus.
2. Description of the Related Art
In absorption type heat pump systems using ammonia, or the like as a refrigerant, the concentration of an ammonia aqueous solution varies according to a current flow. Thus, information regarding the concentration of an aqueous solution is essential in order to evaluate and control the capability of an absorption type heat pump system. In general, a small amount of ammonia aqueous solution can be extracted from the absorption type heat pump system, and the concentration of the ammonic aqueous solution can be measured using titration or density measurement that is an extraction method. However, when such an extraction method is used, it may be difficult to measure the concentration of the ammonia aqueous solution in real-time, or a handling process may be inconvenient and dangerous. In addition, a very small amount of ammonia aqueous solution can be evaporated or may leak during an extraction process. Thus, a measurement error may be generated, and it is difficult to maintain the same conditions after the extraction process has been performed.
In order to solve the problems relating to the extraction method, a method of predicting the concentration of an aqueous solution by using an apparatus for measuring conductance is disclosed in ‘Romero R. j., Herna' ndez J., Ramirez O., and Aguillon J., 1999, Thermodynamic Data in a Falling Film Absorber Operation on Ammonia/Water Solutions, Proc. of the Int. Sorption Heat Pump Conf., pp. 283-289. However, the reliability of concentration predicted by a method of measuring conductance has not been verified yet.